Investigations on invasive nematodes associated with complex insect pests from soil in corn in the environmental conditions of the Republic of Moldova

Corn is one of the major technical field crops in the Republic of Moldova, advantageous in bioecological and productive aspects, which is invaded annually by the harmful organisms with considerable parasitic impact. The phytosanitary control results, carried out annually and seasonally, comparatively in the corn plantations, notice a significant diversity of the specific diseases and of the invasive insects that seriously affect the plants from the germination phases until the harvest. In corn, were established the numerical density values (D. n.), comparative in different ecological areas, on average 15-280 (ex. /100 g soil), with an abundance by 5-25% higher in the autumn than in the spring. Phytoparasitic impact indices the frequency (F %) and intensity (I %) of the phytohelminthological disease level was estimated, being more advanced by 3-30% in the spring-summer period, observed differently depending on the area compared to the autumn period. The structure of parasitic phytonematode complexes was determined counting 20 species, included in 8 families and one order (Tylenchida), classified according to trophic specialization, with the predominance of endo-ectoparasites. It was established the diversity of the associated invasive insect species from the soil: 12 species, 8 families, 3 orders, also, with invasive ectoparasitic impact on corn plants, with the disease degree of 5-40%, detected in all phases of vegetation and sectors investigated.

Bee Guilds’ Responses to Urbanization in Neotropics: A Case Study

The consequent deforestation of urban sprawl is one of the causes of the decline of wild bee communities. In this context, urban green areas (UGA) may play an important role and constitute refuge areas for bees. This study analyzed the influence of UGA conditions and their surroundings in bee guilds’ responses in a medium-sized Brazilian city (Campos dos Goytacazes, RJ). The bees were sampled for 12 months (2017–2018) in 12 UGAs, and bee abundance and species richness were evaluated in guilds considering: nesting behavior, nesting site, and trophic specialization. We used as explanatory variables conditions of UGAs—the number of trees (NT), diameter at breast height (DBH), flower cover (FC), plant richness (PR), percentage of paving (PV)—and of their surroundings—paving (SPV) and the number of buildings (NB). Results showed 80% of eusocial bees, 82% nest in cavities, and 99% were generalists. FC, DBH, and NB mainly explained the responses of different guilds in study areas from all explanatory variables. Thus, this study confirms different responses associated with bee guilds’ attributes. In order to conserve bee diversity, city planning must include more green areas with large flower covers and avoid long corridors of high buildings that can impact bee dispersion.

Trophic specialization on unique resources in one of the most celebrated examples of sympatric speciation, Barombi Mbo crater lake cichlids

Divergent ecological selection often results in trophic niche partitioning and is one of the central processes underlying sympatric speciation. However, there are still few studies of niche partitioning in putative examples of sympatric speciation in the wild. Here we conducted the first quantitative study of dietary niche partitioning in one of the most celebrated examples of sympatric speciation, Barombi Mbo cichlids, using stomach contents and stable isotope analyses. We found little evidence for trophic niche partitioning among any Barombi Mbo cichlids, even among the nine species coexisting in sympatry in the littoral zone. Stable isotope analyses supported these conclusions of minimal dietary overlap. However, we did find extraordinary dietary specialization in some species, including spongivory and feeding on terrestrial ants, both unique feeding strategies among freshwater fishes. Stomach contents of the spongivore (Pungu maclareni) were 20% freshwater sponge, notable considering that only 0.04% of all fishes consume sponges. Overall, we conclude that while there is less trophic niche partitioning than expected among Barombi Mbo cichlids, there is evidence for dietary specialization on rare resources in support of Liem's paradox.

Seasonal quantity dynamics of ground beetles on spring wheat under different fertilization systems

Goal. Determine the dominant species of ground beetles in crops of spring wheat with different fertilization systems and study the seasonal dynamics of the number of ground beetles. Methods. The research was conducted in 2017—2019 years on the experimental field of NSC «Institute of Agriculture of NAAS of Ukraine» in department of plant protection from pests and diseases. Accounting of carabids fauna in accordance with the generally accepted methodology, mainly using Barber soil traps. The ecological characteristics are given using literature data. Results. Specified species composition of the dominant species of carabids in spring wheat crops under different fertilization systems. Represented the seasonal quantity dynamics of mass species of carabids (Bembidion properans S., Harpalus affinis S., Harpalus rufipes D., Poecilus cupreus L., Harpalus distinguendus D.) with mineral (N90P60K90) and organic (with plowing of by-products of the predecessor) fertilizer systems. Population peaks on spring wheat reached maximums in May due to an increase in the activity of species of the spring-summer group of ground beetles (Bembidion properans S., Harpalus distinguendus D., Poecilus cupreus L.), in June — July — due to the summer-autumn group (Harpalus rufipes D. and Harpalus affinis S). Conclusions. The peak activity of carabids in different areas is due to the peculiarities of the biology of each species during the growing season of spring wheat and weather conditions. Of the dominant, the most widespread species with mineral fertilizers was Bembidion properans S., with organic — Harpalus affinis S. There is a difference in the trophic specialization of beetles. In the areas with mineral fertilizer, the number of zoophages and myxophytophages was almost at the same level — 33.4 and 36.6 %, respectively. Organic fertilizer was dominated by myxophytophagous carabids (44%) with a mixed type of diet due to the largest number of species and the number of the genus Harpalus, the percentage of zoophagous was 14.5 %.

Chromosome-scale assembly of the Canary Island endemic spider Dysdera silvatica (Arachnida, Araneae) sheds light on the origin and genome structure of chemoreceptor gene families in spiders

We present the chromosome-level genome assembly of Dysdera silvatica Schmidt, 1981, a nocturnal ground-dwelling spider endemic from the Canary Islands. The genus Dysdera has undergone a remarkable diversification in this archipelago mostly associated with shifts in the level of trophic specialization, becoming an excellent model to study the genomic drivers of adaptive radiations. The new assembly (1.37 Gb; and scaffold N50 of 174.2 Mb), was performed using the chromosome conformation capture scaffolding technique, represents a continuity improvement of more than 4,500 times with respect to the previous version. The seven largest scaffolds or pseudochromosomes cover 87% of the total assembly size and match consistently with the seven chromosomes of the karyotype of this species, including the characteristic large X chromosome. To illustrate the value of this new resource we performed a comprehensive analysis of the two major arthropod chemoreceptor gene families (i.e., gustatory and ionotropic receptors). We identified 545 chemoreceptor sequences distributed across all pseudochromosomes, with a notable underrepresentation in the X chromosome. At least 54% of them localize in 83 genomic clusters with a significantly lower evolutionary distances between them than the average of the family, suggesting a recent origin of many of them. This chromosome-level assembly is the first high-quality genome representative of the Synspermiata clade, and just the third among spiders, representing a new valuable resource to gain insights into the structure and organization of chelicerate genomes, including the role that structural variants, repetitive elements and large gene families played in the extraordinary biology of spiders.

BIODIVERSITY OF HEMIPTERA (HETEROPTERA) OF THE INFRAORDER PENTATOMOMORPHA I OF THE ILE-ALATAU STATE NATIONAL NATURE PARK

The article presents the results of field research conducted in 2020 on the territory of the Ile-Alatau State National Natural Park. As a result of the conducted research, 32 species belonging to 2 families of hemiptera of the infraorder Pentatomomorpha I were identified. Among them, the predominant species composition of the family Lygaeidae is 21 species (66%), and 11 species are known from the family Aradidae (34%). On trophic specialization, they are divided into mycetophagy (11 species), phytophages (21 species, of which politicology – 16 types, wide oligotherapy – 3, narrow oligotherapy – 2). According to the type of food, both taking into account the number and number of species in the complex of hemiptera, phytophages clearly predominate. According to the number of generations per year, the hemiptera of the Ile-Alatau SNNP are divided into 4 groups: acyclic (different stages of development can be found simultaneously throughout the year) – 11 species, monovoltine (one generation per year) - 15 species, bivoltine (two generations per year) – 5 species, polyvoltine (several generations per year) - 1 species. There are 30 species with mesophilic ecology in the study area, only 1 species is hygromesophilus. Among the hemiptera of the Ile-Alatau GNPP, 19 species (61%) overwinter in the imago stage, 11 species (35%) in the imago and larvae stage, and 1 species (4%) in the egg stage.

Trophic specialisation reflected by radular tooth material properties in an “ancient” Lake Tanganyikan gastropod species flock

Background Lake Tanganyika belongs to the East African Great Lakes and is well known for harbouring a high proportion of endemic and morphologically distinct genera, in cichlids but also in paludomid gastropods. With about 50 species these snails form a flock of high interest because of its diversity, the question of its origin and the evolutionary processes that might have resulted in its elevated amount of taxa. While earlier debates centred on these paludomids to be a result of an intralacustrine adaptive radiation, there are strong indications for the existence of several lineages before the lake formation. To evaluate hypotheses on the evolution and radiation the detection of actual adaptations is however crucial. Since the Tanganyikan gastropods show distinct radular tooth morphologies hypotheses about potential trophic specializations are at hand. Results Here, based on a phylogenetic tree of the paludomid species from Lake Tanganyika and adjacent river systems, the mechanical properties of their teeth were evaluated by nanoindentation, a method measuring the hardness and elasticity of a structure, and related with the gastropods’ specific feeding substrate (soft, solid, mixed). Results identify mechanical adaptations in the tooth cusps to the substrate and, with reference to the tooth morphology, assign distinct functions (scratching or gathering) to tooth types. Analysing pure tooth morphology does not consistently reflect ecological specializations, but the mechanical properties allow the determination of eco-morphotypes. Conclusion In almost every lineage we discovered adaptations to different substrates, leading to the hypothesis that one main engine of the flock’s evolution is trophic specialization, establishing distinct ecological niches and allowing the coexistence of taxa.

Species traits affect phenological responses to climate change in a butterfly community

Diverse taxa have undergone phenological shifts in response to anthropogenic climate change. While such shifts generally follow predicted patterns, they are not uniform, and interspecific variation may have important ecological consequences. We evaluated relationships among species’ phenological shifts (mean flight date, duration of flight period), ecological traits (larval trophic specialization, larval diet composition, voltinism), and population trends in a butterfly community in Pennsylvania, USA, where the summer growing season has become warmer, wetter, and longer. Data were collected over 7–19 years from 18 species or species groups, including the extremely rare eastern regal fritillary Speyeria idalia idalia. Both the direction and magnitude of phenological change over time was linked to species traits. Polyphagous species advanced and prolonged the duration of their flight period while oligophagous species delayed and shortened theirs. Herb feeders advanced their flight periods while woody feeders delayed theirs. Multivoltine species consistently prolonged flight periods in response to warmer temperatures, while univoltine species were less consistent. Butterflies that shifted to longer flight durations, and those that had polyphagous diets and multivoltine reproductive strategies tended to decline in population. Our results suggest species’ traits shape butterfly phenological responses to climate change, and are linked to important community impacts.

SPECIES OF THE GENUS ADIALYTUS (HYMENOPTERA, BRACONIDAE: APHIDINAE) IN THE FAUNA OF UKRAINE

Genus Adialytus is represented in Europe by four species, only two of which are recorded in the fauna of Ukraine: Adialytus ambiguus (Haliday, 1834) and Adialytus salicaphis (Fitch, 1855). Data on the distribution of these species, their trophic specialization, and habitat associations are provided on the basis of material from the collection of I. I. Schmalhausen Institute of Zoology of the National Academy of Sciences of Ukraine (SIZK) and previous publications. A. ambiguus is a broad oligophagous, however, parasitizing mostly species of the genus Sipha on Poaceae. In Ukraine, A. ambiguus is found in the Forest-Steppe zone (Kyiv, Cherkasy, Kirovohrad, Poltava regions), in the Zone of broad-leaved forests of Ukraine (Ternopil region). Adialytus salicaphis is registered for now only in the Zone of mixed forests of Ukraine (Kyiv region). This species is a narrow oligophagous and develops on aphids of the genus Chaitophorus on Salix and Populus. Its potential areal might include also Forest-Steppe zone (more probably on the Left Bank of Dnieper River) and plains of big rivers in the Steppe zone of Ukraine. The potential role of these species as biocontrol agents is discussed: A. ambiguus could be recommended for consideration as a new candidate for biocontrol of Sipha spp. and probably Rhopalosiphum spp, on cereal crops in Ukraine, while A. salicaphis is not a species of practical importance in the country now. We consider quite probable finding in Ukraine another well-distributed European species A. thelaxis (Starý, 1961), which is a parasitoid of aphids of the genus Thelaxes on oaks.

Species composition of Ground beetles (Coleoptera: Carabidae) on spring wheat in the Right-Bank Forest-Steppe of Ukraine

Goal. To clarify the species composition of carabids in spring wheat agrocenosis, to determine the dominant species, to compare the number of ground beetles on application of mineral fertilizers and organic nutrients. Methods. Field method — accounting of insects on the sowing of spring wheat in accordance with generally accepted methods. Laboratory method — determination of the species composition of ground beetles. The study was conducted in 2017—2019 on the basis of National Research Center «Institute of Agriculture of NAAS of Ukraine», department of plant protection against pests and diseases (Chabany, Kyiv-Sviatoshynskyi district, Kyiv region). Results. The species composition of carabid beetles on the sowings of spring wheat under modern conditions has been specified. 41 species of ground beetles from 15 genera were found. On application of mineral fertilizers, the dominant species were Bembidion properans Stephens, 1828, Harpalus affinis Schrank, 1781, Harpalus rufipes De Geer, 1774, Poecilus cupreus Linnaeus, 1758, Harpalus distinguendus Duftschmid, 1812. H. affinis Schr., H. rufipes Deg., H. distinguendus Duft., P. cupreus L., Calathus fuscipes Goeze, 1777, Harpalus smaragdinus Duftschmid, 1812 were dominant species on application of organic nutrients. In both variants, Broscus cephalotes Linnaeus, 1758, Poecilus punctulatus Schaller, 1783, Poecilus versicolor Sturm, 1824, Microlestes minutulus Goeze, 1777 were subdominant species. The ratio of trophic groups of carabid beetles in the agrocenosis of spring wheat has been established. The seasonal dynamics of the number of ground beetles has been reflected. Conclusions. In the first variant (mineral fretilizers) 40 species of carabids were registered, in the second (organic nutrients) — 35. Among all identified species (according to trophic specialization) the number of phytophages and zoophages was similar — 21 and 19, but in the experimental variants their ratio differed. The average number of ground beetles during 2017—2019 was: variant 1 — 30.8 specimens per trap, variant 2 — 28.1 specimens per trap.